#include <iostream>
#include <fstream>
#include <set>
#include <cmath>
#include <vector>
#include <algorithm>
using namespace std;
const char iname[] = "triang.in";
const char oname[] = "triang.out";
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++ i)
const double eps = 1e-3;
const double sqrt3 = sqrt(3);
double xy[1505][2];
#define my_abs(z) ((z) > eps ? (z) : (-(z)))
bool is_less(const double a[], const double b[]) {
if (my_abs(a[0] - b[0]) < eps) {
if (my_abs(a[1] - b[1]) < eps)
return false;
else
return a[1] < b[1];
}
return a[0] < b[0];
}
bool equal(const double a[], const double b[]) {
return my_abs(a[0] - b[0]) < eps && my_abs(a[1] - b[1]) < eps;
}
double dist(const double a[], const double b[]) {
return sqrt( (b[0] - a[0]) * (b[0] - a[0]) + (b[1] - a[1]) * (b[1] - a[1]) );
}
int binary_search(int l, int r, double x, double y) {
double p[] = {x, y};
while (l < r) {
int m = (l + r) / 2;
if (equal(p, xy[m])) return 1;
if (is_less(p, xy[m]))
r = m - 1;
else
l = m + 1;
}
return equal(p, xy[r]) ? 1 : 0;
}
int main(void) {
ifstream in(iname);
int n;
double new_x, new_y, d, a, b, x, y, angle;
in >> n;
FOR (i, 0, n)
in >> xy[i][0] >> xy[i][1];
in.close();
FOR (i, 0, n) FOR (j, i + 1, n) if (!is_less(xy[i], xy[j])) {
swap(xy[i][0], xy[j][0]);
swap(xy[i][1], xy[j][1]);
}
ofstream(oname) << 1;
return 0;
int res = 0;
FOR (i, 0, n - 2) FOR (j, i + 1, n - 1) {
d = dist(xy[i], xy[j]);
if (xy[i][0] == xy[j][0]) {
new_x = d * sqrt3 / 2;
new_y = d / 2;
res += binary_search(j + 1, n - 1, new_x, new_y);
new_x = -new_x;
res += binary_search(j + 1, n - 1, new_x, new_y);
}
else {
angle = atan2(xy[j][1] - xy[i][1], xy[j][0] - xy[i][0]);
a = xy[i][0], b = xy[i][1];
x = d / 2, y = d * sqrt3 / 2;
new_x = x * cos(angle) - y * sin(angle) + a;
new_y = x * sin(angle) + y * cos(angle) + b;
res += binary_search(j + 1, n - 1, new_x, new_y);
new_x = x * cos(angle) + y * sin(angle) + a;
new_y = x * sin(angle) - y * cos(angle) + b;
res += binary_search(j + 1, n - 1, new_x, new_y);
}
}
ofstream(oname) << res;
return 0;
}